New Delhi, Oct. 9 -- Prime Minister Narendra Modi inaugurated a new international airport in India's financial capital, Mumbai, on Wednesday, marking a step forward in expansion of the country's fast-growing aviation network.

Navi Mumbai International Airport is expected to begin operating in December and will make Mumbai the only metropolitan area in the world's most populous country to have a second international airport. It aims to become a key passenger and cargo hub in Asia and to help ease congestion at Chhatrapati Shivaji Maharaj International Airport, one of the country's busiest.

The airport built by the Adani Group for an estimated $2.2 billion is the latest project underscoring India's push to modernize infrastructure and str...